This disclosure is generally directed to curable phase change inks, such as radiation-curable phase change inks, and their use in forming images, such as through inkjet printing. More specifically, this disclosure is directed to radiation-curable phase change inks, such as ultraviolet-light-curable phase change inks, that comprise at least one isosorbide monomer having at least one functional group.
Inkjet printing systems are known in the art, and thus extensive description of such devices is not required herein. Phase change or “hot melt” inks are desirable for ink jet printers because they remain in a solid phase at room temperature during shipping, long term storage, and the like. In addition, the problems associated with nozzle clogging as a result of ink evaporation with liquid ink jet inks are largely eliminated, thereby improving the reliability of the ink jet printing. Further, in phase change ink jet printers wherein the ink droplets are applied directly onto the final recording substrate (for example, paper, plastic, cardboard, and the like), the droplets solidify quickly upon contact with the substrate, so that migration of ink along the printing medium is substantially prevented and dot quality is improved.
Curable phase change inks typically contain a curable monomer that serves as a reactive diluent and is often the major component (50 to about 55 percent by weight) of the curable phase change ink composition. Examples of curable monomers include diacrylate molecules derived from petroleum-based diols, such as propoxylated neopentyl glycol diacrylate. However, curable phase change inks may also cause certain problems such as (1) increased accumulation in greenhouse gases and/or accumulation of non-biodegradable materials and (2) ink shrinkage (the purging of excess ink) caused by formation of air bubbles jet lines. These issues may be due to presence of the petroleum based curable monomers in the curable phase change ink, which can lead to poor abrasian resistance, poor adhesion and poor offset.